In the past decades, technological advancements in industrial process control and automation have contributed greatly to improve the productivity of virtually all manufacturing industries throughout the world. In that, process control is extensively used in industry and enables mass production of continuous processes such as oil refining, paper manufacturing, chemicals, power plants and many other industries. Process control enables automation, with which a small staff of operating personnel can operate a complex process from a central control room.
In the present scenario, almost all the instruments widely used in process control are equipped with different remote ports like RS232/RS422/RS485, RJ45 (Ethernet port) and some of them with CAN/LIN bus to enable remote connectivity to the devices. The scope here is restricted to the operation of valves alone. There are different types of valves based on the application to control the pressure or flow of any liquid, air, gas and the like.
Most of the vendors provide a Local Control Unit (LCU) to control the valves which need to be wired to valves. Among them, few vendors do provide a Remote Terminal Unit (RTU) also so as to enable the user to control a group of valves from the control room. But this RTU is also mostly wired. Most of the deployments have been tested and proven using different types of wireless communications such as Bluetooth, ZigBee, and RFID in process control and automation.